The present invention relates generally to apparatus for washing dishes, pots, cookware, silverware, utensils, glasses, trays, and like articles, and more particularly, the present invention relates to a warewasher that reduces or prevents the release of a blast of steam or hot air laden with water vapor and mist from the wash/rinse chamber of the warewasher when a door, curtain or the like of the warewasher is opened immediately following a wash and/or rinse cycle.
So called “door type” warewashers are commonly utilized by institutional organizations, such as prisons, schools, and the like, which are required to clean a large quantity of dishware, cookware, pots, pans, trays, utensils, silverware, drinking glasses, and/or like articles on a daily basis. Door-type warewashers include freestanding and undercounter units and can be specifically designed to handle a specific type of article, such as glassware or pots and pans. Door-type warewashers are also typically referred to as “stationary rack” warewashers since the rack loaded with the dishware and like articles remains substantially stationary within the chamber during the entire washing and rinsing process until the door of the warewasher is opened and the rack is removed. Typically, a door-type warewasher has a substantially rectangular wash/rinse chamber accessed by a door which, when closed, forms at least a part of one of the walls of the wash/rinse chamber. The chamber is adapted to receive one or more racks loaded with dishware and the like which are to be washed and rinsed within the chamber after the door is closed. Examples of commercially available door-type warewashers include Insinger Commander 18-5 Automatic Single Tank Door Type Dishwasher and Insinger Door Type, Single Tank Scullery Machine manufactured by Insinger Machine Company of Philadelphia, Pa.
So called “conveyor type” warewashers are also commonly utilized by institutional organizations, such as prisons, schools, and the like, which are required to clean a large quantity of dishware, cookware, pots, pans, trays, utensils, silverware, drinking glasses, and/or like articles on a daily basis. Conveyor-type warewashers are generally elongate and include opposite input and output ends between which dishware travel during a cleaning, rinsing, and/or sanitizing cycle. Some conveyor type warewashers are designed to receive and convey separate removable racks from the input end to the output end. Rackless systems, flight systems, and other systems are also utilized and may be designed to convey specific articles, such as trays or some other article. Conveyor-type warewashers typically do not have rigid doors; rather, some form of flexible curtain is typically utilized at the input and output ends which deflect to an open position when articles pass through the input and output ends.
A typical cleaning cycle may include a wash period, a hot rinse period, and a short dwell period between the wash and rinse periods or at the end of the cycle. Merely for purposes of example, a complete cycle may run for about 60 seconds, 90 seconds, or other predetermined period of time.
A significant amount of hot, highly-humidified air or steam and mist is generated within a warewasher by the end of a cleaning cycle, particularly as a result of the final rinse which is typically accomplished at a high temperature. Thus, when a door of the warewasher is opened at the end of a cleaning cycle to remove a rack of cleaned and/or sanitized dishware or the like, a cloud of steam and hot air laden with water vapor and mist is released/expelled into the surrounding work space or area within the room in which the warewasher is located, such as a commercial kitchen or the like. This can create safety problems and generally create discomfort for its operators.
Since commercial dishwashing and warewashing equipment produce a significant amount of steam vapor, many municipal, state, federal and military guidelines require that all commercial foodservice facilities (i.e., public school cafeterias, hospital kitchens, hotel dish rooms, U.S. Navy battleship galleries, etc.) employ a dedicated ventilation system for the removal of the steam vapor. Thus, an operator of the above referenced warewashers must typically install and operate a comprehensive ventilation system to provide proper ventilation and maintain an efficient kitchen work environment.
Such ventilation systems are typically costly to construct, difficult to develop using existing ductwork, can involve significant complexities, and require frequent maintenance. In addition, the use of such ventilation hoods, which typically are run at 100% capacity throughout the day, can result in a significant waste of energy and energy costs including electrical energy costs to operate the hood and the loss of HVAC-treated room air.
Although the aforementioned door-type, stationary-rack warewashers and conveyor-type warewashers function satisfactorily for their intended purposes, there is a need for improved dishwashers and warewashers which prevent the release of a cloud of steam and hot air laden with water vapor and mist upon the opening of a door of the warewasher following the completion of each cleaning cycle. Such a system should provide the benefit of eliminating the need for an externally vented hood system thereby providing initial cost savings related to purchasing and installing a hood ventilation system and continual savings relative to eliminating the undesired venting of HVAC-treated room air. In addition, the warewashers/dishwashers should provide energy savings, provide reduced noise levels, provide improved indoor air quality, and enhance machine operator safety and comfort.